import Data.List.Split
import Data.Char as Char

main = do
    let content = [1002,4,3,4,33]	
    let input = []
    let output = operation content content 0 input []  
    mapM putStrLn (map show output)

getList :: String -> [Int]
getList = map read . splitOn ","

changeInput :: [Int] -> Int -> Int -> [Int]
changeInput (begin:_:_:input) input1 input2= [begin] ++ [input1] ++ [input2] ++ input

func :: [Int] -> Int -> Int -> Int
func xs x y = do
	let input = changeInput xs x y
        head (compute input input 0 [] [] )	

compute :: [Int] -> [Int] -> Int -> [Int] -> [Int] -> [Int]
compute (99:_) state index input output = state
compute (op:x:y:z:_) state index input output= 
        compute (drop newindex state) newstate newindex input output 
        where
	    sum = if op == 1 then
                  (state !! x) + (state !! y)
	          else 
                 (state !! x) * (state !! y)
            split = splitAt z state
            newstate = (fst split) ++ [sum] ++ (drop 1 (snd split))
            newindex = index + 4

operation :: [Int] -> [Int] -> Int -> [Int] -> [Int] -> [Int]
operation (99:_) state index input output = 
	state
operation (op:x:y:z:_) state index input output 
  | last (digits op) == 1 = do
	   let newindex = index + 4
           let newstate = add (fillup (revertdigs op) 5) x y z state
	   operation (drop newindex newstate) newstate newindex input output
  | last (digits op) == 2 = do 
           let newindex = index + 4
           let newstate = mult (fillup (revertdigs op) 5) x y z state
	   operation (drop newindex newstate) newstate newindex input output
  | last (digits op) == 3 = do
	   let newindex = index + 2
           let newstate = put (fillup (revertdigs op) 3) x (head input) state
           let newinput = drop 1 input  
           operation (drop newindex newstate) newstate newindex newinput output

  | last (digits op) == 4 = do
	   let newindex = index + 2
	   let newoutput = out (fillup (revertdigs op) 3) output x state
	   let newinput = drop 1 input  
           operation (drop newindex state) state newindex input newoutput


add :: [Int] -> Int -> Int -> Int -> [Int] -> [Int]
add (op1:op2:m1:m2:m3:_) p1 p2 p3 state = 
	 insert state sum p3 
	 where
		sum = (getValue m1 p1 state)  + (getValue m2 p2 state)

mult :: [Int] -> Int -> Int -> Int -> [Int] -> [Int]
mult (op1:op2:m1:m2:m3:_) p1 p2 p3 state = 
	 insert state sum p3 
	 where
		sum = (getValue m1 p1 state) * (getValue m2 p2 state)

put :: [Int] -> Int -> Int -> [Int] -> [Int]
put(op1:op2:m1:_) p1 input state =
         insert state input p1

out :: [Int] -> [Int] -> Int -> [Int] -> [Int]
out (op1:op2:m1:_) output p1 state =
	output ++ [(state !! (getValue m1 p1 state))]

insert ::  [Int] -> Int -> Int -> [Int]
insert xs value index = do
                let split = splitAt index xs
                (fst split)++ [value] ++ (drop 1 (snd split))

digits :: Int -> [Int]
digits = map Char.digitToInt . show

revertdigs :: Int -> [Int]
revertdigs 0 = []
revertdigs x = x `mod` 10 : revertdigs (x `div` 10)

fillup :: [Int] -> Int -> [Int]
fillup array x = array ++ (replicate (x - (length array)) 0)

getValue :: Int -> Int -> [Int] -> Int
getValue 0 index array = array !! index
getValue 1 index array = index